Electrical Circuits 6.P.3A.1

Electrical Energy  Electrical energy is energy that is caused by moving electric charges. Since the electric charges are moving, this is a form of kinetic energy. The faster the electric charges are moving the more electrical energy they carry.

Electrical Energy ….continue  Energy flowing in an electrical circuit resulting from the movement of electrons

1. Source of electrical energy  Examples include:  The electrical energy in a battery comes from stored chemical energy  The electrical energy in a solar cell comes from light energy from the sun  The electrical energy in outlets comes from chemical energy (burning fossil fuels) which powers a generator in a power plant.

2. A conductor  A conductor of electrical energy (wire) that connects all parts of the electric circuits.

3. Transformer  A transformer changes the electrical energy into something else (a light bulb changes electrical energy into radiant energy)

Activity 3.1A – Complete Circuits Focus Question: How can energy be transformed in an electric circuit?

Activity 3.1A: Complete Circuits 1. Collect 1 battery 2 wires 1 light bulb 2. Find at least 4 different ways to light the bulb. 3. In your science notebook, draw one complete circuit that made the light bulb light, and draw one that did not work.

Activity 3.1A: Complete Circuits  What made the circuit work?  What made the circuit not work?  Which circuit would light the light bulb? Why?

Electric Circuit An electric circuit must be a complete, unbroken path through which the electricity flows.  The purpose of a switch is to control whether a circuit is closed (electricity flows) or open (electricity cannot flow).

An electric circuit contains…  1. A source of electrical energy that provides the “push” that makes current move around a circuit.  2. A conductor of electrical energy (wires)  3. A transformer which converts the electrical energy into another form like light and heat.  4. Switch which opens and closes the circuits.

Types of Electric Circuits 1 Open 2 Closed 3 Series Circuit 4 Parallel Circuit

Open- Circuit  If the circuit is not closed, then electricity cannot flow; this is called an open circuit.  Since the electricity is not flowing, the transformer cannot change the electrical energy into another type of energy.

Closed- circuit  The wire (conductor) must connect the power source to the transformer and then connect back to the power source to create a complete, or closed circuit.

Closed circuit …. continue  A closed circuit allows the electricity to flow and the transformer to change the electrical energy into another type of energy.  Example: a light bulb with two wires attached to it, one going to the negative end of a battery and one to the positive end, and the light bulb lights up.

Series Circuit  In a series circuit there is only one path for electricity to flow through.  If any part of the circuit is open, the series circuit will not work.

Parallel Circuit  In a parallel circuit there is more than one path for electricity to flow through.  Electricity can flow around an opening in a parallel circuit.

Conclusion of all Circuit  In Open Circuit the Path is not connected.  In Closed Circuit each wire is connected and has a closed path.  In Parallel Circuit It has more than one Path.  In Series Circuit there is only one path.

PARALLEL OR SERIES?

Think about it….  Think of some things that provide or use electricity around your house.  Put those item/appliances into categories based on what they do. I.E.:  Make heat  Make sound  Make light  Make movement/moving

1.What type of energy goes into the bulb? 2.What is the source of the energy? 3.Why type of energy comes out of the bulb? 4.Where does it go? Think back to… Activity 3.1A– Complete Circuits

(4 corner transformations)  Light  Heat  Mechanical Motion  Sound

Transformation of Electrical Energy  Electrical energy can be transformed to other forms of energy in a circuit. For example:  Light  Sound  Heat  Mechanical motion

The Law of Conservation of Energy Energy cannot be created or destroyed. Energy may be transformed from one form to another, but the total amount of energy never changes. Recall

Light  Light is electromagnetic Radiation which makes possible to see the things.  The natural source of light is Sun and other sources and examples are Fire and Lamp.

Light  Electrical energy can be transformed into light energy in an electrical circuit if a light bulb is included in the circuit.

Light….. Continue  The transformation in this case might be that:  chemical energy in a battery is transformed into electrical energy in the circuit which is transformed into light and heat energy in the light bulb. Battery (device ) Electric Energy Light bulb (device) Light Energy Heat Energy

Heat  Electrical energy can be transformed into heat energy in an electric circuit if a toaster, stove, or heater is included in the circuit.

Heat……continue Fuel (Chem. En.) Heat Ener gy Gener ator (Mech. Energy.) Circuit (Elec. En.) Heater (Heat En.)

Heat…….Continue  The transformation in this case might be that –  Chemical energy from the fuel at the power plant is transformed into heat energy  This heat energy is transformed into mechanical energy to turn a generator  The generator transforms the mechanical energy into electrical energy  Then the electrical energy is the circuit is transformed into heat energy in the heater

Sound  Sound is the movement of energy through substances in the forms of waves.

Focus Question: How can energy be transformed in an electric circuit? Activity 3.1B-

Activity 3.1B: Transformations in Electric Circuits 1. Build a circuit which includes: 1 battery (in a battery holder) 2wires 1switch 1 motor Be sure that the motor will turn on and off when the switch is opened and closed. 2. Draw the circuit in your notebook 3. Observe and record the energy transformation in the chart. Remember to use all of your senses for observations.

Mechanical Motion  Electrical energy can be transformed into the energy of mechanical motion if a fan or moto is added to the circuit.  Transformation in this case might be that chemical energy in a battery is transformed into electrical energy in the circuit which is transformed into the energy of mechanical motion by the fan or motor.

1. What is the purpose of the switch in the circuit? Does it transform energy? 2. What kind of energy does most of the energy in the circuit eventually become? Electric Circuits – Activity 3.1